/* ==========================================================================
   3D TUNNEL RUSH - DESIGN SYSTEM & STYLESHEET
   Version: v4.15.0
   ========================================================================== */

.hidden {
  display: none !important;
  opacity: 0 !important;
  pointer-events: none !important;
}

:root {
  --bg-dark: #020617;
  --bg-card: rgba(15, 23, 42, 0.75);
  --bg-card-border: rgba(56, 189, 248, 0.2);
  --cyan-glow: #00f0ff;
  --purple-glow: #a855f7;
  --pink-glow: #ec4899;
  --amber-glow: #f59e0b;
  --text-main: #f8fafc;
  --text-muted: #94a3b8;
  --font-family: 'Inter', system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  --transition-fast: 0.2s cubic-bezier(0.4, 0, 0.2, 1);
  --shadow-neon: 0 0 25px rgba(0, 240, 255, 0.35);
}

* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
  user-select: none;
  -webkit-user-select: none;
  touch-action: manipulation;
}

html, body {
  overscroll-behavior: none;
  touch-action: manipulation;
}

body {
  background-color: var(--bg-dark);
  color: var(--text-main);
  font-family: var(--font-family);
  overflow-x: hidden;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  background-image: 
    radial-gradient(circle at 50% 20%, rgba(0, 240, 255, 0.08) 0%, transparent 50%),
    radial-gradient(circle at 80% 80%, rgba(168, 85, 247, 0.08) 0%, transparent 50%);
}

/* Header & Version Bar */
header.app-header {
  width: 100%;
  max-width: 1100px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 12px 20px;
  margin-bottom: 8px;
  background: var(--bg-card);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border: 1px solid var(--bg-card-border);
  border-radius: 16px;
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.4);
}

.brand-title {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 800;
  font-size: 1.25rem;
  letter-spacing: 1px;
  background: linear-gradient(135deg, var(--cyan-glow), var(--purple-glow));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  text-transform: uppercase;
}

.version-badge {
  background: rgba(0, 240, 255, 0.12);
  color: var(--cyan-glow);
  border: 1px solid rgba(0, 240, 255, 0.4);
  padding: 4px 10px;
  border-radius: 20px;
  font-size: 0.75rem;
  font-weight: 700;
  letter-spacing: 0.5px;
}

.header-controls {
  display: flex;
  align-items: center;
  gap: 12px;
}

/* Icon Buttons */
.icon-btn {
  background: rgba(255, 255, 255, 0.06);
  border: 1px solid rgba(255, 255, 255, 0.15);
  color: var(--text-main);
  padding: 8px 14px;
  border-radius: 10px;
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-size: 0.85rem;
  font-weight: 600;
  transition: var(--transition-fast);
}

.icon-btn:hover {
  background: rgba(0, 240, 255, 0.15);
  border-color: var(--cyan-glow);
  color: #ffffff;
  box-shadow: 0 0 12px rgba(0, 240, 255, 0.3);
}

.icon-btn.active {
  background: var(--cyan-glow);
  color: #020617;
  border-color: var(--cyan-glow);
  font-weight: 700;
  box-shadow: var(--shadow-neon);
}

/* Game Container & Viewport Wrapper */
.game-layout {
  position: relative;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 12px;
  width: 100%;
  max-width: 1040px;
  padding: 0 10px;
}

/* Dynamic Screen Resolution-Adaptive Viewport Frame */
.viewport-frame {
  position: relative;
  background: #000;
  border-radius: 16px;
  overflow: hidden;
  border: 2px solid var(--cyan-glow);
  box-shadow: 0 0 30px rgba(0, 240, 255, 0.25), inset 0 0 15px rgba(0, 0, 0, 0.8);
  transition: width 0.3s ease, height 0.3s ease, border-color 0.3s ease;
  display: flex;
  justify-content: center;
  align-items: center;
  margin: 0 auto;
}

/* 2D & Anaglyph Mode Viewport Class: Dynamic Square */
.viewport-frame.mode-single {
  width: min(96vw, min(850px, calc(100vh - 65px)));
  height: min(96vw, min(850px, calc(100vh - 65px)));
  max-width: 100%;
}

/* Parallel & Cross-Eye 3D Viewport Class: Dynamic 2:1 Aspect Ratio */
.viewport-frame.mode-dual {
  width: min(98vw, min(1600px, calc((100vh - 65px) * 2)));
  height: min(49vw, min(800px, calc(100vh - 65px)));
  max-width: 100%;
}

/* Center guide divider line for SBS stereo views */
.sbs-divider {
  position: absolute;
  top: 0;
  left: 50%;
  width: 2px;
  height: 100%;
  background: linear-gradient(to bottom, transparent, rgba(0, 240, 255, 0.5), transparent);
  pointer-events: none;
  z-index: 5;
  display: none;
}

.mode-dual .sbs-divider {
  display: block;
}

/* Canvas Element */
#gameCanvas {
  width: 100%;
  height: 100%;
  display: block;
}

/* HUD Overlay inside Viewport */
.hud-overlay {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  pointer-events: none;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  padding: 16px;
  z-index: 10;
}

.hud-top {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
}

.score-box {
  background: rgba(2, 6, 23, 0.65);
  backdrop-filter: blur(8px);
  padding: 8px 16px;
  border-radius: 12px;
  border: 1px solid rgba(0, 240, 255, 0.3);
}

.score-label {
  font-size: 0.7rem;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 1px;
}

.score-value {
  font-size: 1.5rem;
  font-weight: 800;
  color: #ffffff;
  font-family: monospace;
}

.hud-center-stats {
  display: flex;
  gap: 12px;
}

.stat-pill {
  background: rgba(2, 6, 23, 0.65);
  backdrop-filter: blur(8px);
  padding: 6px 12px;
  border-radius: 20px;
  border: 1px solid rgba(255, 255, 255, 0.15);
  font-size: 0.8rem;
  font-weight: 700;
  display: flex;
  align-items: center;
  gap: 6px;
}

.stat-pill.speed { border-color: var(--cyan-glow); color: var(--cyan-glow); }
.stat-pill.shield { border-color: var(--pink-glow); color: var(--pink-glow); }
.stat-pill.multiplier { border-color: var(--amber-glow); color: var(--amber-glow); }

.hud-bottom {
  display: flex;
  justify-content: space-between;
  align-items: flex-end;
}

.view-mode-indicator {
  background: rgba(168, 85, 247, 0.2);
  border: 1px solid var(--purple-glow);
  color: #ffffff;
  padding: 4px 12px;
  border-radius: 8px;
  font-size: 0.75rem;
  font-weight: 700;
  letter-spacing: 0.5px;
  text-transform: uppercase;
}

/* Modals & Screens (Start / Pause / Game Over) */
.modal-overlay {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: rgba(2, 6, 23, 0.85);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  z-index: 20;
  padding: 20px;
  text-align: center;
  pointer-events: auto;
  transition: opacity 0.3s ease;
}

.modal-overlay.hidden {
  opacity: 0;
  pointer-events: none;
}

.modal-card {
  background: var(--bg-card);
  border: 1px solid var(--bg-card-border);
  box-shadow: 0 10px 40px rgba(0, 0, 0, 0.6), 0 0 20px rgba(0, 240, 255, 0.2);
  border-radius: 20px;
  padding: 24px 32px;
  max-width: 440px;
  width: 90%;
  display: flex;
  flex-direction: column;
  gap: 16px;
  align-items: center;
}

.modal-title {
  font-size: 2rem;
  font-weight: 900;
  background: linear-gradient(135deg, #ffffff, var(--cyan-glow));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  text-transform: uppercase;
  letter-spacing: 2px;
}

.action-btn {
  background: linear-gradient(135deg, var(--cyan-glow), #00a8ff);
  color: #020617;
  font-size: 1.1rem;
  font-weight: 800;
  padding: 12px 32px;
  border: none;
  border-radius: 12px;
  cursor: pointer;
  text-transform: uppercase;
  letter-spacing: 1px;
  box-shadow: 0 4px 15px rgba(0, 240, 255, 0.4);
  transition: transform 0.15s ease, box-shadow 0.15s ease;
  width: 100%;
}

.action-btn:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 20px rgba(0, 240, 255, 0.6);
}

.action-btn:active {
  transform: translateY(0);
}

/* Stereo Controls Bar (3D Toolbar below Canvas) */
.controls-toolbar {
  width: 100%;
  background: var(--bg-card);
  backdrop-filter: blur(12px);
  border: 1px solid var(--bg-card-border);
  border-radius: 16px;
  padding: 14px 20px;
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  align-items: center;
  gap: 12px;
}

.mode-selector {
  display: flex;
  gap: 6px;
  background: rgba(0, 0, 0, 0.4);
  padding: 4px;
  border-radius: 12px;
  border: 1px solid rgba(255, 255, 255, 0.08);
}

.mode-btn {
  background: transparent;
  border: none;
  color: var(--text-muted);
  padding: 8px 14px;
  border-radius: 8px;
  font-size: 0.85rem;
  font-weight: 700;
  cursor: pointer;
  transition: var(--transition-fast);
}

.mode-btn:hover {
  color: var(--text-main);
}

.mode-btn.active {
  background: var(--cyan-glow);
  color: #020617;
  box-shadow: 0 0 12px rgba(0, 240, 255, 0.4);
}

/* Parameter Sliders Panel */
.params-panel {
  display: flex;
  align-items: center;
  gap: 16px;
  flex-wrap: wrap;
}

.slider-group {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 0.8rem;
  color: var(--text-muted);
  font-weight: 600;
}

.slider-group span.val {
  color: var(--cyan-glow);
  font-family: monospace;
  font-weight: 700;
  min-width: 36px;
}

input[type="range"] {
  -webkit-appearance: none;
  appearance: none;
  background: rgba(255, 255, 255, 0.15);
  height: 6px;
  border-radius: 3px;
  outline: none;
  width: 100px;
}

input[type="range"]::-webkit-slider-thumb {
  -webkit-appearance: none;
  appearance: none;
  width: 16px;
  height: 16px;
  border-radius: 50%;
  background: var(--cyan-glow);
  cursor: pointer;
  box-shadow: 0 0 8px var(--cyan-glow);
}

/* Mobile Virtual Keypad Overlay */
.virtual-keypad {
  width: 100%;
  max-width: 400px;
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  grid-template-rows: repeat(2, 60px);
  gap: 10px;
  margin-top: 10px;
  justify-content: center;
}

.vk-btn {
  background: rgba(15, 23, 42, 0.8);
  border: 1px solid rgba(0, 240, 255, 0.3);
  color: var(--cyan-glow);
  border-radius: 12px;
  font-size: 1.4rem;
  display: flex;
  justify-content: center;
  align-items: center;
  font-weight: bold;
  cursor: pointer;
  backdrop-filter: blur(6px);
  transition: background 0.1s ease, transform 0.1s ease;
  user-select: none;
  -webkit-user-select: none;
}

.vk-btn:active {
  background: var(--cyan-glow);
  color: #020617;
  transform: scale(0.95);
}

.vk-btn.boost-btn {
  grid-column: span 3;
  background: linear-gradient(135deg, rgba(236, 72, 153, 0.3), rgba(168, 85, 247, 0.3));
  border-color: var(--pink-glow);
  color: #ffffff;
  font-size: 0.95rem;
  font-weight: 800;
  letter-spacing: 1px;
}

/* Keypad Visibility class */
.virtual-keypad.hidden-keypad,
.virtual-keypad-2btn.hidden-keypad {
  display: none !important;
}

/* 2-Button Keypad Layout */
.virtual-keypad-2btn {
  width: 100%;
  max-width: 500px;
  display: flex;
  gap: 16px;
  margin-top: 12px;
  justify-content: center;
}

.vk-btn-large {
  flex: 1;
  height: 60px;
  background: rgba(15, 23, 42, 0.85);
  border: 2px solid var(--cyan-glow);
  color: var(--cyan-glow);
  border-radius: 14px;
  font-size: 1.1rem;
  font-weight: 800;
  cursor: pointer;
  backdrop-filter: blur(8px);
  box-shadow: 0 4px 15px rgba(0, 240, 255, 0.2);
  transition: background 0.1s ease, transform 0.1s ease;
  user-select: none;
  -webkit-user-select: none;
}

.vk-btn-large:active {
  background: var(--cyan-glow);
  color: #020617;
  transform: scale(0.96);
}

/* Info Drawer Modal */
.info-drawer {
  position: fixed;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  background: var(--bg-card);
  border: 1px solid var(--cyan-glow);
  border-radius: 20px;
  padding: 24px;
  width: 90%;
  max-width: 500px;
  z-index: 100;
  box-shadow: 0 0 40px rgba(0, 240, 255, 0.3);
}

.info-drawer h3 {
  color: var(--cyan-glow);
  margin-bottom: 12px;
  font-size: 1.3rem;
}

.info-drawer p {
  color: var(--text-muted);
  font-size: 0.9rem;
  line-height: 1.5;
  margin-bottom: 10px;
}

.info-drawer ul {
  margin-left: 20px;
  color: var(--text-main);
  font-size: 0.85rem;
  line-height: 1.6;
}

.close-drawer-btn {
  margin-top: 16px;
  background: var(--cyan-glow);
  color: #020617;
  border: none;
  padding: 8px 18px;
  border-radius: 8px;
  font-weight: 700;
  cursor: pointer;
}

/* Focus Eyes Countdown Banner */
.focus-banner {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  background: rgba(2, 6, 23, 0.88);
  backdrop-filter: blur(12px);
  border: 2px solid var(--cyan-glow);
  box-shadow: 0 0 30px rgba(0, 240, 255, 0.5);
  border-radius: 20px;
  padding: 18px 28px;
  text-align: center;
  z-index: 15;
  pointer-events: none;
}

.focus-title {
  font-size: 0.9rem;
  font-weight: 800;
  color: var(--cyan-glow);
  text-transform: uppercase;
  letter-spacing: 1px;
}

.focus-countdown {
  font-size: 3.5rem;
  font-weight: 900;
  color: #ffffff;
  font-family: monospace;
  margin: 4px 0;
  text-shadow: 0 0 20px var(--cyan-glow);
}

.focus-sub {
  font-size: 0.8rem;
  color: var(--text-muted);
}

/* Responsive adjustments */
@media (max-width: 768px) {
  header.app-header {
    padding: 10px 14px;
  }
  .controls-toolbar {
    flex-direction: column;
    align-items: stretch;
  }
  .mode-selector {
    justify-content: center;
  }
  .params-panel {
    justify-content: center;
  }
}

/* Floating PWA Internet Update Banner */
.update-banner {
  position: fixed;
  bottom: 24px;
  left: 50%;
  transform: translateX(-50%);
  z-index: 9999;
  background: rgba(15, 23, 42, 0.94);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border: 1.5px solid var(--cyan-glow);
  box-shadow: 0 8px 32px rgba(0, 240, 255, 0.4);
  padding: 12px 24px;
  border-radius: 50px;
  display: flex;
  align-items: center;
  gap: 16px;
  transition: all 0.3s ease;
}

.update-content {
  display: flex;
  align-items: center;
  gap: 16px;
}

.update-text {
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--text-main);
}

.update-text strong {
  color: var(--cyan-glow);
}

.update-btn {
  background: linear-gradient(135deg, var(--cyan-glow), #0284c7);
  color: #020617;
  font-weight: 800;
  font-size: 0.85rem;
  border: none;
  padding: 8px 18px;
  border-radius: 30px;
  cursor: pointer;
  box-shadow: 0 0 12px rgba(0, 240, 255, 0.5);
  transition: transform 0.15s ease, box-shadow 0.15s ease;
}

.update-btn:hover {
  transform: scale(1.05);
  box-shadow: 0 0 20px rgba(0, 240, 255, 0.8);
}

/* ==========================================================================
   v4.0.0 TWO-PAGE ARCHITECTURE & SOLID BLOCK HUD STYLES
   ========================================================================== */

.page-container {
  width: 100%;
  max-width: 1100px;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 12px;
  padding: 10px;
  transition: opacity 0.3s ease;
}

.page-container.hidden {
  display: none !important;
  opacity: 0 !important;
  pointer-events: none !important;
}

/* Page 1: Menu Content */
.menu-content {
  width: 100%;
  display: flex;
  flex-direction: column;
  align-items: center;
}

.start-card {
  background: var(--bg-card);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border: 1px solid var(--bg-card-border);
  box-shadow: 0 10px 40px rgba(0, 0, 0, 0.6), 0 0 25px rgba(0, 240, 255, 0.2);
  border-radius: 20px;
  padding: 28px;
  width: 100%;
  max-width: 850px;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 16px;
}

.controls-guide-box {
  background: rgba(0, 240, 255, 0.08);
  padding: 16px 20px;
  border-radius: 14px;
  border: 1px solid rgba(0, 240, 255, 0.25);
  text-align: left;
  width: 100%;
}

/* Page 2: Gameplay Screen Unified Bottom Controls Toolbar */
.game-bottom-toolbar {
  width: 100%;
  max-width: 1050px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 12px;
  padding: 6px 12px;
  margin-top: 4px;
  background: var(--bg-card);
  backdrop-filter: blur(10px);
  border: 1px solid var(--bg-card-border);
  border-radius: 16px;
  box-shadow: 0 4px 15px rgba(0, 0, 0, 0.4);
}

.bottom-bar-group {
  display: flex;
  align-items: center;
  gap: 8px;
}

.icon-btn.icon-only {
  padding: 8px 12px;
  font-size: 1.15rem;
  min-width: 42px;
  min-height: 42px;
  justify-content: center;
  border-radius: 12px;
}

.virtual-keypad-inline {
  display: flex;
  gap: 8px;
  align-items: center;
  justify-content: center;
  flex: 1;
}

.virtual-keypad-inline .vk-btn-large {
  flex: 1;
  max-width: 130px;
  height: 42px;
  font-size: 0.85rem;
  font-weight: 800;
  background: rgba(15, 23, 42, 0.85);
  border: 1px solid rgba(0, 240, 255, 0.4);
  color: var(--cyan-glow);
  border-radius: 12px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: all 0.15s ease;
}

.virtual-keypad-inline .vk-btn-large:active {
  background: var(--cyan-glow);
  color: #020617;
  transform: scale(0.95);
}

/* Solid Block HUD (Outside 3D Viewport, Zero-Parallax 3D Stereo HUD Bar) */
.solid-block-hud {
  width: 100%;
  max-width: 1000px;
  background: #020617; /* Solid dark background, zero transparency */
  border: 2px solid var(--cyan-glow);
  box-shadow: 0 0 20px rgba(0, 240, 255, 0.3);
  border-radius: 14px;
  padding: 8px 12px;
  display: flex;
  justify-content: space-around;
  align-items: center;
  margin-top: 4px;
}

.hud-block-half {
  flex: 1;
  display: flex;
  justify-content: space-around;
  align-items: center;
  gap: 4px;
}

.hud-block-half.hud-right-eye {
  border-left: 2px solid rgba(0, 240, 255, 0.4);
  padding-left: 6px;
}

.hud-block-item {
  display: flex;
  flex-direction: column;
  align-items: center;
  min-width: 45px;
}

.hud-label {
  font-size: 0.65rem;
  font-weight: 800;
  color: var(--text-muted);
  letter-spacing: 1px;
  text-transform: uppercase;
}

.hud-val {
  font-size: 0.95rem;
  font-weight: 700;
  color: var(--text-main);
  font-family: monospace;
}

.hud-val-bold {
  font-size: 1.3rem;
  font-weight: 900;
  color: #ffffff;
  font-family: monospace;
}

.hud-val.cyan, .hud-val-bold.cyan { color: var(--cyan-glow); }
.hud-val.pink, .hud-val-bold.pink { color: var(--pink-glow); }
.hud-val.amber, .hud-val-bold.amber { color: var(--amber-glow); }
.hud-val.purple, .hud-val-bold.purple { color: var(--purple-glow); }

.update-close-btn {
  background: rgba(255, 255, 255, 0.1);
  border: 1px solid rgba(255, 255, 255, 0.2);
  color: var(--text-muted);
  font-size: 0.85rem;
  padding: 4px 8px;
  border-radius: 50%;
  cursor: pointer;
  transition: all 0.15s ease;
  line-height: 1;
}

.update-close-btn:hover {
  background: rgba(239, 68, 68, 0.2);
  border-color: #ef4444;
  color: #ffffff;
}

/* ==========================================================================
   MOBILE LANDSCAPE, VR HEADSET & RAYNEO SMART GLASSES VIEWPORT OPTIMIZATION
   ========================================================================== */
@media (max-height: 550px) {
  #gamePage {
    padding: 2px 4px !important;
    justify-content: flex-start !important;
  }

  .viewport-frame {
    margin: 0 auto !important;
  }

  .game-bottom-toolbar {
    margin-top: 2px !important;
    padding: 2px 6px !important;
    gap: 6px !important;
    border-radius: 10px !important;
  }

  .icon-btn.icon-only {
    min-width: 32px !important;
    min-height: 32px !important;
    padding: 3px 6px !important;
    font-size: 0.90rem !important;
  }

  .virtual-keypad-inline {
    gap: 4px !important;
  }

  .virtual-keypad-inline .vk-btn-large {
    height: 30px !important;
    font-size: 0.72rem !important;
    max-width: 90px !important;
    border-radius: 8px !important;
  }
}